Chest Physiotherapy With Positive Airway Pressure: A Pilot Study of Short-Term Effects on Sputum Clearance in Patients With Cystic Fibrosis and Severe Airway Obstruction

BACKGROUND: The periodic administration of positive airway pressure combined with directed cough could aid mucus clearance in patients with cystic fibrosis (CF) and severe airway obstruction.

OBJECTIVE: To compare the short-term effect of positive expiratory pressure (PEP) physiotherapy via mask (mask PEP), continuous positive airway pressure (CPAP), and noninvasive positive-pressure ventilation (NPPV) physiotherapies on amount of sputum collected.

METHODS: Directed cough was standardized for each patient and used as the control treatment. We studied 17 patients with CF (mean ± SD age 28 ± 7 y) and severe airway obstruction (forced expiratory volume in the first second 25 ± 6% of predicted) admitted for pulmonary exacerbation. Mask PEP, CPAP, NPPV, and the control treatment (directed cough) were administered in a random sequence. Each patient received each treatment twice a day (in 70-min sessions) for 2 consecutive days. We measured the wet and dry weight of sputum collected and the number of directed and spontaneous coughs during each session. Spirometry and pulse oximetry were conducted before and after each session. For mask PEP, CPAP, and NPPV, each patient gave a subjective score for the efficacy and tolerability of the treatment, compared to the control treatment.

RESULTS: There was no statistically significant difference in the dry weight of sputum collected: mask PEP 0.9 ± 0.6 g, CPAP 0.8 ± 0.4 g, NPPV 0.9 ± 0.6 g, control treatment 1.0 ± 0.8 g. There was a statistically significant difference in the wet weight of sputum collected: mask PEP 15.8 ± 5.5 g, CPAP 13.7 ± 5.5 g, NPPV 13.2 ± 5.0 g, control treatment 14.0 ± 5.0 g (p < 0.05), but that difference became nonsignificant when we took into account the number of spontaneous coughs. There were no statistically significant changes in the spirometry and pulse-oximetry values. The patients' subjective efficacy scores were similar for mask PEP, CPAP, and NPPV. Less fatigue was reported after NPPV and CPAP than after mask PEP.

CONCLUSIONS: There were no differences in sputum clearance or pulmonary-function measures between mask PEP and short-term administration of either CPAP or NPPV combined with directed cough. After mask PEP these patients felt more tired than after CPAP or NPPV secretion-clearance therapy.